West Nile Virus infected bird found southwest of Palermo

OROVILLE &GT;&GT; West Nile virus has been detected in Butte County for the first time this year.

Tuesday Butte County Mosquito and Vector Control District announced a dead crow found southwest of Palermo has tested positive for the virus.

The virus, which is spread by mosquitos, can infect humans but the vast majority of people don't even know the have the disease. But if a horse is infected the situation is dire.

Richard Price, Butte County's farm commissioner, said in a telephone interview there is no treatment for a horse once the animal is infected.

He said the virus attacks the animal's central nervous system. They stagger in circles and can't swallow.

Matt Ball, manager of the mosquito control district, described what a horse stricken with the virus goes through as "among the top five most disturbing things I have ever seen in my life."

Price said while there is no treatment, horses can be inoculated against the virus.

There have been no cases of West Nile Virus in horses since 2012, and Price believes that is because horse owners have been aggressive in getting their animals immunized.

Ball said his district attacks the sources of the infection.

Two different species of mosquito — Northern house mosquito and the Western encephalitis mosquito — transmit the virus.

The Northern house variety, technically called Culex pipien, can breed in almost any bit of stagnant water around a home. Poorly maintained birdbaths, random buckets, or even water trapped in roof gutters can all provide a brooding site for the insects.

He said people should drain all of these stagnant pools. For containers like horse troughs that can't be readily drained, the district will provide the land owner with "mosquitofish" — Gambusia affinis — that will happily eat mosquito larvae in the body of water. People can contact the district to request mosquitofish at 533-6038.

Ball this species has adapted thoroughly to the environment provided around human habitation.

The Western encephalitis mosquito reproduces in ponds, rice fields and other areas where there is still water.

While there is no real chance of eradicating these two disease vectors, people can take steps to protect themselves.

These critters can't tolerate extended exposure to the heat of the day, they are usually active between about a half hour after sunset and a half hour before sunrise.

Ball said the Northern house variety likes to come into a house and rest on a wall. He said the insect will actually watch a human being and after the person has been still for about 30 minutes, getting ready to sleep or some other reason, the mosquito will swoop in and feed.

The district manager said people are often unaware that they have provided either of these species with a meal.

"These aren't the type that bite you and make you itch," he explained.

Ball said he is personally "very, very sensitive to mosquito bites and these don't even make me itch."

He said people should avoid being outside, as far as it is possible, during the hours the mosquitos are active. Ball encouraged individuals who are going to be outside to wear long sleeve shirts, long pants, shoes and socks, and apply insect repellent.

The district keeps track of the West Nile Virus mosquito population by keeping tabs on the dead birds and even squirrels that are reported. He said in a given year his office will receive between 1,000 and 2,500 reports of dead critters.

Many of them are not a variety of bird or in a physical condition that they meet the criterion to be tested. When they are the right kind and in the necessary condition, they are shipped to a lab at the UC Davis.

The lab does the definitive study to determine if the virus is involved.

He said this crow's discovery is little later in the year than he would expect to see the first infected bird.

He asked the public to report dead birds. The birds can be reported by calling 533-6038 or 342-7350, or on the district web site at www.BCMVCD.com.

When it comes to humans, the CDC says 70 to 80 percent of the people who become infected with the virus do not develop any symptoms.

"About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.

"Less than 1 percent of people who are infected will develop a serious neurologic illness, such as encephalitis or meningitis, inflammation of the brain or surrounding tissues. The symptoms of neurologic illness can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis."

Agency says less than 10 percent of the individuals who develop the most severe form of the illness die.